Part #6309 1 Knife Set (3) Length: 18" 1/2" center hole. gator mulching knife Replaces: GRASSHOPPER 320236 GRASSHOPPER 320237 GRASSHOPPER 320239 STENS 302-244 STENS 320-040 SUNBELTB1SB90929 Windsor 51-2245 Windsor 51-2290